Rescuers dug frantically in the rubble of a school dormitory, hunting for dozens of children believed trapped.

More than 70 children had already been saved from the debris of the school. Terrified parents prayed and screamed, waiting for news.

The prime minister, Recep Tayyip Erdogan, said nearly 100 people were killed, while the housing minister, Zeki Ergezen, said the death toll could be 150 throughout the region.

City official Sevket Turan in Bingol, the epicentre of the quake, said 90 people were dead and close to 1,000 injured.

Crews were working to rescue up to 100 primary and middle school students still buried under the four-story dormitory that collapsed in the village of Celtiksuyu.

By midday, 72 children had been rescued, said rescue worker Muhsin Balgi.

Mr Balgi said the voices of children screaming could be heard from the debris.

"We hope another 50 students will be saved," Balgi said, adding that many were feared dead.

Some 198 students - aged seven to 16 - were sleeping in the dormitory when the quake hit before dawn. Most of the students were sons of poor Kurdish farmers from surrounding villages that do not have schools and are difficult to access, leading many to sleep overnight there.

Five students and one teacher were found dead, the mayor of Bingol, Feyzullah Karaaslan, said.

"My friends are waiting for help in there. They were calling for help as they were pulling me out," 12-year-old Veysel Dagdelen was quoted as saying by the Anatolia news agency after he was rescued.

The earthquake measured 6.4 on the Richter scale and struck at 3.27 am (0127 BST) today. Its epicentre was just outside the city of Bingol, 430 miles east of Ankara, the Kandilli seismology center in Istanbul said.

At least 25 buildings and a bridge collapsed in central Bingol, a city of 250,000 inhabitants, the mayor said. Damage could be seen throughout the city, where the streets were filled with terrified residents.

Bingol is a poor, rural area in the predominantly Kurdish south-east that suffered for years from fierce fighting between the Turkish army and Kurdish autonomy-seeking rebels.

The earthquake damaged power and telephone lines in the area. More than 100 aftershocks hit the region.

At the remnants of the school dormitory, soldiers, rescuers and locals worked their way through the huge concrete slabs and tangled steel with cranes and jackhammers to try to save surviving students. Many students were being treated for their injuries on mattresses laid out near the flattened building.

Naim Gencgul, a 15-year-old boy, was pulled out of the rubble with a broken arm.

"The whole building was on top of me. We all started screaming," he said.

Relatives rushed toward soldiers every time a rescued boy was carried out on a stretcher to check if their children had been saved. Women, some barely speaking Turkish, wailed and prayed for their children.

Meantime, parents questioned the quality of the school's construction.

"The stable I built did not collapse, but the school did," said Abdullah Gunala, the father of a rescued student.

Mr Erdogan visited the quake area, and said proper inspections had not been carried out and that shoddy material had been used to build the school.

"Investigations will be launched and the guilty will be prosecuted," he said.

Thousands of poorly-built buildings collapsed when two large earthquakes struck western Turkey in 1999, killing some 18,000 people.

Nazim Karabulut, a resident of Bingol, described the school as a "terrible construction." "Nobody ever learned their lessons," he said.

Bingol's state hospital was seriously damaged in the quake and scores of injured were being treated outside.

"Many will have to spend the night on the streets because they cannot enter their buildings," Mr Karaaslan said.

The Red Crescent sent 2,100 tents, 13,000 blankets, as well as mobile kitchens, generators, ambulances, and four tons of food supplies, rescue authorities said. Soldiers, emergency workers and mountaineers with rescue experience were also headed to the area.

The tremor was felt in the nearby provinces of Erzincan, Tunceli, Erzurum, Kayseri and Sivas.

The earthquake lasted 17 seconds, said Gulay Barbarasoglu of the Istanbul observatory.

Earthquakes are frequent in Turkey, which lies on the active North Anatolian fault. A 1971 quake in Bingol killed 900 people.